Stents and stent delivery assemblies are utilized in a number of medical procedures and situations, and as such their structure and function are well-known. Intraluminal stents are used to maintain the patency of blood vessels and other body lumens. Use of stents to keep open a coronary or other artery after an angioplasty procedure has been performed is now a common practice. Stents are also commonly used in the treatment of urological disorders.
Stents that may be delivered to a restricted coronary artery or other body lumen, expanded to a larger diameter as by a balloon catheter, and left in place in the dilated lesion are described in many patent documents including U.S. Pat. No. 4,740,207, Kreamer; U.S. Pat. No. 5,007,926, Derbyshire; U.S. Pat. No. 4,733,665, Palmaz; U.S. Pat. No. 5,026,377, Burton, et al; U.S. Pat. No. 5,158,548, Lau, et al; U.S. Pat. No. 5,242,399, Lau, et al; U.S. Pat. No. 5,292,331, Boneau; U.S. Pat. No. 5,344,426, Lau, et al; U.S. Pat. No. 5,415,664, Pinchuck; U.S. Pat. No. 5,453,090, Martinez, et al; U.S. Pat. No. 4,950,227, Savin; U.S. Pat. No. 5,403,341, Solar; U.S. Pat. No. 5,108,416, Ryan, et al; EP 707837 A1, Scheiban; WO 96/03092, Medinol Ltd; U.S. Pat. No. 6,019,789, Dinh, et al; U.S. Pat. No. 6,776,793, Brown, et al; US 20020095208 A1, Goran; US 20030083732 A1, Stinson and US 20030083736 A1, Brown, et al, the entire contents of all of which are incorporated herein by reference.
In advancing a balloon expandable stent through a body vessel to the deployment site, there are a number of important considerations. The stent must be able to securely maintain its axial position on the delivery catheter. The stent, particularly its distal and proximal ends, are sometimes protected to prevent distortion of the stent, and minimize trauma to the vessel walls. Balloon expandable stent delivery and deployment assemblies are known which utilize restraining means that overlay the stent, or a portion thereof, during delivery. U.S. Pat. No. 5,968,069, Dusbabek, et al, and U.S. Pat. No. 6,733,520, Yang, et al, provide examples of such stent delivery and deployment systems.
Other methods for improving stent securement have involved modifications of the balloon/stent interface. Heated crimping, and other heat and/or pressure-based processing are known and used to improve securement, in some cases together with an accompanying chemical treatment or imposition of an intervening structure. Examples of such methods are included in U.S. Pat. No. 6,187,013, Stoltze et al; U.S. Pat. No. 5,836,965, Jendersee, et al; U.S. Pat. No. 5,976,181, Whelan, et al; U.S. Pat. No. 6,245,076, Yan; U.S. Pat. No. 6,464,718, Miller, et al; U.S. Pat. No. 6,620,191, Svensson; and U.S. Pat. No. 6,666,880, Chiu, et al.